Description of problem:

I did the following setting related to localnet_learn_fdb option by using hieradata in T-H-T.

parameter_defaults:
ControllerExtraConfig:
neutron::config::plugin_ml2_config:
ovn/localnet_learn_fdb:
value: true
ovn_nb_global/fdb_age_threshold:
value: 300
ovn_nb_global/fdb_removal_limit:
value: 50000

This setting was reflected to /var/lib/config-data/puppet-generated/neutron/etc/neutron/plugins/ml2/ml2_conf.ini in controller nodes correctly like:

~~~
[ovn]
fdb_age_threshold=300
localnet_learn_fdb=True
: (snip)
[ovn_nb_global]
fdb_removal_limit=50000
~~~

However, I checked these settings of OVN NB DB with `ovn-nbctl list NB_Global` after running `openstack overcloud deploy`, but the value of `fdb_removal_limit`(50000) wasn't reflected like the following:

~~~

1. podman exec ovn_controller ovn-nbctl --columns=options list NB_Global
   options : {fdb_removal_limit="0", ignore_lsp_down="false", mac_binding_removal_limit="0", mac_prefix="aa:b9:38", max_tunid="16711680", northd_internal_version="23.09.4-20.29.0-71.6", svc_monitor_mac="ba:40:2c:c7:a4:a3"}

   ~~~

Additionally, I run the following command in the controller nodes, but it was also not reflected.

~~~

1. systemctl restart tripleo_neutron_api
2. systemctl restart tripleo_ovn_cluster_north_db_server
3. systemctl restart tripleo_ovn_cluster_northd.service
4. systemctl restart tripleo_ovn_controller.service
   ~~~

Version-Release number of selected component (if applicable):

openstack-neutron-18.6.1-17.1.20231025110810.el9ost
ovn23.09-23.09.3-5.el9fdp.x86_64

How reproducible:

Always

Steps to Reproduce:
1. Run `overcloud deploy` with the above `ControllerExtraConfig` setting.
2. Check OVN NB DB with `ovn-nbctl list NB_Global`

Actual results:

The value of `fdb_removal_limit` in NB DB wasn't reflected as the value of the parameter in ml2_conf.ini

Expected results:

The value of `fdb_removal_limit` will be reflected correctly